Unit skylight system

ABSTRACT

An improved skylight system comprises a unitary light transmitting skylight lens having a main lens body, an outwardly projecting horizontal support flange, a surrounding downwardly and outwardly extending skirt panel, and a horizontal lower attachment lip extending from the skirt panel. The attachment lip is held in a channel formed by an upper hold-down flange and a cooperating lower flange of a mounting frame. The lens is fitted over a roof curb and attached thereto by driving fasteners through a vertical attachment collar that depends from the inner edge of the lower flange of the mounting frame into the curb.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention related to skylights in general and more particularly to skylights having a light transmitting lens that caps a roof curb and which provides a peripheral attachment lip that terminates below the top of the curb and is secured to the curb below the curb top using a metallic mounting frame.

2. Description of Related Art

A fixed unit skylight consists of a light transmitting lens that is supported by and attached to a structural perimeter frame that generally forms part of the roof of a building. Commonly, the lens of a unit skylight is attached to and supported by the curb using a glazed or otherwise sealed mounting frame. The mounting frame may consist of multiple sections all of which must be joined together and attached to the top of the curb. The assembly of the frame sections and mounting of the lens to the curb all create potential leak points and opportunities for system failure, especially over time as the system experiences wear.

One example of a prior art unit skylight system is shown in FIG. 1 in which a lens or lens assembly 1 is mounted to a curb 2 using a combination of a mounting bracket 3 that is secured over the top of the curb 2 and a retaining clip 4. Sealing tape 5 is applied to the top of the curb 2 to achieve a water resistant seal between the mounting bracket 3 and curb 2. Generally the mounting bracket 3 and retaining clip 4 are formed from extruded aluminum and sections thereof are joined around and on top of the curb 2. The mounting bracket 3 includes an upstanding flange 3.1 that provides a mounting platform 3.2 on which to rest the lens assembly 1. The mounting bracket is secured to the curb 2 with threaded fasteners 6.

The retaining clip 4 includes a horizontal part 7 which overlays the lens assembly 1 and a vertical part 8 which is joined to the upstanding flange 3.1 with fasteners 9 thereby capturing the lens assembly 1 between the mounting platform 3.2 below and the horizontal part 7 of the retaining clip 4 above.

Opportunities for system failure in a unit skylight system such as that described above generally increase with the complexity of the mounting system. In systems such as that shown in FIG. 1, through either substandard installation procedures or simple wear-and-tear on the system over time, leakage may occur through the mounting bracket 3, between the mounting bracket 3 and retaining clip 4, between the lens assembly 1 and the retaining clip 4, and around the perimeter of the curb 2 between adjoining sections of the mounting system.

In some prior art mounting frames a condensation grill, such as upturned flange 3.3 shown in FIG. 1, extends inwardly into the daylighting aperture bounded by the curb, thereby measurably reducing the amount of light which can be conveyed by the daylighting aperture to a living space in the building below.

BRIEF SUMMARY OF THE INVENTION

An improved unit skylight system comprises a unitary light transmitting lens having a main lens body and an integral horizontal support flange extending from and surrounding the main lens body. An integral downwardly depending circumferential skirt panel extends outwardly from the support flange and an integral horizontal attachment lip extends outwardly from the lower edge of the skirt panel. The support flange rests on the top surface of a structural curb of a roof, such that the main lens body spans the full dimension of the daylighting aperture formed by the curb. With the support flange of the lens resting on the curb, the lower attachment lip of the lens projects outwardly below the top of and away from the curb.

A mounting frame includes a generally U-shaped portion having an upper hold-down flange and a parallel lower flange. The lower attachment lip of the lens is captured in a recess formed between the upper and lower flanges. An attachment collar depends from the inner edge of the lower flange and is spaced from the curb to accommodate roofing material. The attachment collar is fixed to the curb with fasteners that pass through the roofing material into the curb, thereby urging the U-shaped portion of the mounting frame onto the lower attachment lip and holding the lens onto the curb.

The lens thus covers the entire geographic span of the aperture formed by the curb, the perimeter of the lens flows over and below the top of the curb, and is affixed to the curb below the top surface of the curb thereby avoiding water intrusion problems associated with prior art unit skylight systems and eliminating undesirable encroachment into the light-admitting aperture.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

FIG. 1 is an elevation view of a prior art unit skylight system.

FIG. 2A is an elevational view of an improved unit skylight system according to the invention.

FIG. 2B is an exploded view of the elements of the improved unit skylight system shown in FIG. 2A.

FIG. 3 is an exploded upper perspective view of the lens and mounting frame thereof over a structural curb.

FIG. 4 is a close-up perspective view of a corner of the lens and mounting frame thereof.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

An improved unit skylighting system is illustrated in FIGS. 2A-4 and is referred to generally at 10 in FIGS. 2A and 2B. A unitary light transmitting skylight lens 12 is mounted over a structural curb 14. The curb 14 is generally rectangular as shown in FIG. 3, but it should be understood that the precise shape of the curb is not critical to the invention and need not be limited to rectangular shapes. The curb 14 is erected on a roof and has a top surface 16, an outer side or sides 18, and an inner side or sides 20. The top surface 16 has an inner edge 22 where it intersects with the inner side 20. The inner sides 20 of the curb 14 define a daylighting aperture 23 through which light is admitted into the interior of the building below.

The skylight lens 12 is of molded unitary construction, is at least semi-transparent, and may have a prismatic lower surface 24 for diffusing light. The lens 12 includes an integral horizontal support flange 26 which extends outwardly from and surrounds the main lens body 28. See FIG. 3. The lens 12 is constructed to conform to the shape of the top of the curb 14 so that when it is positioned on the curb 14 the support flange 26 rests on the top surface 16 of the curb 14 as shown in FIG. 2A. A layer of curb seal tape 30 is provided on the top surface 16 of the curb 14 to ensure a water resistant seal between the lens 12 and curb 14. In the illustrated embodiment, the sloped perimeter edge 32 of the main lens body 28 meets the support flange 26 at the inner edge 22 of the top surface 16 of the curb 14. This maximizes the area of the support surface 26 that rests on the top surface 16 of the curb 14 and makes for an aesthetically pleasing presentation when viewing the skylight from the interior of the building.

With continuing reference to FIGS. 2A and 2B, an outer portion 34 of the support flange 26 extends outwardly beyond the outer side 18 of the curb 14 and a downwardly depending integral skirt panel 36 extends outwardly from the distal edge 38 of the support flange 26. An integral horizontal lower attachment lip 40 extends outwardly from the lower edge 41 of the skirt panel 36. A mounting frame 42 is installed over the attachment lip 40 and secured to the curb 14 as discussed below more particularly.

The mounting frame 42 includes a U-shaped portion 44 having an upper hold-down flange 46 and a lower flange 48 interconnected by a spine 50. A recess 52 is defined between the upper and lower flanges 46, 48 and sized to receive the attachment lip 40. The recess 52 is of a sufficient height to accommodate the attachment lip 40 and a spline 54 to achieve a secure fit between the upper and lower flanges 46, 48. The lower flange 48 is provided with a roughened surface 56 on which a bead of sealant 58 may be deposited. The sealant 58 acts as an adhesive between attachment lip 40 and lower flange 48 and makes a water resistant joint between the attachment lip 40 and mounting frame 42 that prevents water from penetrating to the outer side 18 of the curb 14.

An attachment collar 60 depends vertically from the lower flange 48 of the mounting frame 42 and is spaced a distance D from the outer side 18 of the curb 14 for accommodating roofing material (not shown) that is built up on the side of the curb during a typical skylight installation. Fasteners 62 are introduced through apertures 64 in the attachment collar 60 (see FIG. 4) and driven through the roofing material and into the curb 14 as shown in FIG. 2A. The fasteners 62 drive the attachment collar 60 against the roofing material and toward the curb 14 thereby urging the mounting frame 42 over and onto the lower attachment lip 40 of the lens 12 and holding the lens 12 onto the curb 14.

The mounting frame 42 is assembled in sections in a normal installation usually by cutting the ends of adjoining sections at a 45 degree angle as shown in FIG. 4. The sections are joined by driving a fastener 65 through a corner hole 66 in the end of one section 42A into the screw-centering channel 68 located along the spine 50 of an adjoining section 42B of the mounting frame. The screw-centering channel 68 is provided in each section of the mounting frame 46, but is exposed for use as a screw-centering channel when a section is cut on a diagonal as seen in FIG. 4.

The lens 12 and mounting frame 42 are assembled in a manufacturing facility and then transported to the roof where the assembly is positioned over the curb 14 and securely fastened into place as described above.

An improved unit skylight system according to the invention is simple in construction, reduces opportunities for leakage of water into the underlying structure, may be installed quickly and with ease, and maximizes the light aperture through which light penetrates to the building interior. The system will also accommodate flashing.

An embodiment of an improved unit skylighting system according to the invention has been described and illustrated. Although the invention has been described and illustrated in detail, it should be clearly understood that the disclosure is illustrative and by way example only and is not to be taken as limiting, the spirit and scope of the present invention being limited only by the terms of the appended claims and their legal equivalents. 

We claim:
 1. A unit skylighting system for mounting a unit skylight on a roof, the roof having a structural curb bounding an aperture for admitting light into a building interior, the curb having a top surface and an outer side, the unit skylighting system comprising: a unitary light transmitting lens having a main lens body, a horizontal support flange extending outwardly from said main lens body, a downwardly depending skirt panel extending outwardly from said support flange, and a lower attachment lip, said support flange resting directly on the top surface of the curb such that said main lens body spans the full aperture, said skirt panel having a lower edge spaced from the outer side of the curb, said lower attachment lip extending outwardly from said lower edge, and a mounting frame including a U-shaped portion having an upper hold-down flange, a lower flange, a channel defined by said upper and lower flanges, and an attachment collar depending downwardly from said lower flange, said lower attachment lip of said lens received in said channel, and fasteners attaching said attachment collar to the curb below the top surface thereof, tightening said fasteners driving said attachment collar toward and securing said attachment collar to the curb thereby urging the U-shaped portion of said mounting frame onto said lower attachment lip and holding said lens onto the top surface of the curb.
 2. The improved unit skylighting system of claim 1, the top surface of the curb having an inner edge, wherein: the main lens body of said lens has a sloped perimeter edge, and the support flange of said lens meets said sloped perimeter edge at the inner edge of the curb.
 3. The improved unit skylighting system of claim 1 wherein: said support flange includes an outer portion that extends outwardly beyond the outer side of the curb.
 4. The improved unit skylighting system of claim 1 wherein: said lower flange is parallel to and vertically spaced from said support flange.
 5. The improved unit skylighting system of claim 3 wherein: said attachment collar is horizontally spaced from the outer side of the curb, and said support flange, said skirt panel, said attachment collar, and the curb define an unobstructed downwardly-facing opening for accommodating roofing material applied to the curb.
 6. The improved unit skylighting system of claim 5 wherein: said attachment collar is horizontally spaced from the outer side of the curb by approximately ½″.
 7. A method for installing a unit skylight on a roof, the roof having a structural curb bounding an aperture for admitting light into a building interior, the curb having a top surface and an outer side, the method comprising: securing a mounting frame to a unitary light transmitting lens by inserting a lower attachment lip of said lens into a channel of a U-shaped portion of said mounting frame, said lower attachment lip extending outwardly from the lower edge of a skirt panel, said skirt panel depending downwardly and extending outwardly from a horizontal support flange, said support flange extending outwardly from a main lens body of said lens, said channel defined by an upper hold-down flange of said mounting frame and a lower flange thereof disposed parallel to said upper flange, applying a water resistant seal between said lower flange and said lower attachment lip, positioning said support flange onto the top surface of the curb such that said skirt panel and said lower attachment lip extend outwardly from and below the top surface of the curb, and attaching said mounting frame to the curb thereby securing said lens on the curb.
 8. The method for installing a unit skylight on a roof of claim 7 further comprising: attaching said mounting frame to the curb by fastening an attachment collar to the curb, said attachment collar depending from an inner edge of the lower flange of said mounting frame.
 9. A unit skylighting system for mounting a unit skylight on a roof having a structural curb bounding an aperture for admitting light into a building interior, the curb having a top surface and an outer side, the unit skylighting system comprising: a unitary light transmitting lens having a main lens body, a horizontal support flange extending outwardly from said main lens body, a downwardly depending skirt panel extending outwardly from said support flange, and a lower attachment lip, said support flange resting directly on the top surface of the curb such that said main lens body spans the full aperture, said support flange including an outer portion that extends outwardly beyond the outer side of the curb, said skirt panel having a lower edge spaced from the outer side of the curb, said lower attachment lip extending outwardly from said lower edge, and a mounting frame including a U-shaped portion having an upper hold-down flange, a lower flange, a channel defined by said upper and lower flanges, and an attachment collar depending downwardly from said lower flange and spaced from the outer side of the curb, said lower attachment lip of said lens received in said channel, an unobstructed downwardly-facing opening defined by said support flange, said skirt panel, said attachment collar, and the curb, said opening for accommodating roofing material applied to the curb, and threaded fasteners attaching said attachment collar to the curb below the top surface thereof, tightening said fasteners driving said attachment collar toward and securing said attachment collar to the curb thereby urging the U-shaped portion of said mounting frame onto said lower attachment lip and holding said lens onto the top surface of the curb. 